serial: earlycon: Add support for big-endian MMIO accesses

Support command line parameters of the form:
earlycon=<name>,io|mmio|mmio32|mmio32be,<addr>,<options>

This commit seem to be needed even after commit:
serial: 8250: Add support for big-endian MMIO accesses
c627f2ceb6

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/kernel-parameters.txt

@@ -959,14 +959,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 		uart[8250],io,<addr>[,options]
 		uart[8250],mmio,<addr>[,options]
 		uart[8250],mmio32,<addr>[,options]
+		uart[8250],mmio32be,<addr>[,options]
 		uart[8250],0x<addr>[,options]
 			Start an early, polled-mode console on the 8250/16550
 			UART at the specified I/O port or MMIO address.
 			MMIO inter-register address stride is either 8-bit
-			(mmio) or 32-bit (mmio32).
-			If none of [io|mmio|mmio32], <addr> is assumed to be
-			equivalent to 'mmio'. 'options' are specified in the
-			same format described for "console=ttyS<n>"; if
+			(mmio) or 32-bit (mmio32 or mmio32be).
+			If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
+			to be equivalent to 'mmio'. 'options' are specified
+			in the same format described for "console=ttyS<n>"; if
 			unspecified, the h/w is not initialized.
 
 		pl011,<addr>